In systems processing articles it is often necessary to turn an article around, or to flip it, so that a side of an article facing in one direction before the flip faces into the opposite direction after the flip. For example, if an article is to be inspected, it may be necessary to inspect the entire article; one possibility to achieve this is to flip the article between consecutive inspection steps, so that different sides of the article can be inspected. Analogous statements apply if opposite sides of an article or object need to be worked on. If articles are to be processed at high throughput, flipping the articles has to be done at a high rate.
Several types of flipping systems are known. One type is a hand-over flipping system. In such a system the article or object is held by a first handler, for example a vacuum nozzle, rotated by 90 degrees, handed over to a second handler, which performs a further rotation by 90 degrees. In this way, a flip of the object or article can be achieved. In such a type of system, the input position, i.e. the position from where the article is picked by the first handler, is usually different from the output position. Furthermore, the hand-over flipping system has to complete the flipping operation for one article, before it can commence the flipping operation for a further article.
A further type of flipping system is a rotational flipping system. The article to be flipped is placed into a bottom nest, which then is covered with a top nest. This assembly is rotated by 180 degrees. The former bottom nest, now on top, is removed, and the flipped article can be removed from the former top nest. Such a system has to complete the flipping operation for one article, before it can commence the flipping operation for a further article.
Yet another type of flipping system is a spoke-wheel flipping system. The article is picked up by a handler, for example a vacuum nozzle, from an input location. The handler, carrying the article, then rotates by 180 degrees, which implies a rotation of the article by 180 degrees. The article is then picked from the handler by a further handler. With this approach, the distance between the input position, from where the article is picked up, and the output position, from where the article is picked after the rotation, is at least twice the length of the handler.
If a flipping operation for one article has to be completed before a flipping operation for a further article can be started, this is a limiting factor on the throughput of the flipping system and may adversely affect the throughput of any processing system using such a flipping system. If flipping systems are used for which the input position of an article is different from the output position of the article, the workflow in and the configuration of a processing system have to take this change of position into account. Therefore, if the articles are to be processed without flipping in some occasions, changes to the configuration of the processing system become necessary, as either the change of position of the article has to be achieved without a flip of the article, or an alternative path of the articles through the processing system has to be established.